roundel vs armorial bearing

roundel and armorial bearing both are nouns.

Word	Noun	Adjective	Verb	Adverb
roundel	Yes	No	No	No
armorial bearing	Yes	No	No	No

As nouns, armorial bearing is a hypernym of roundel; that is, armorial bearing is a word with a broader meaning than roundel:

roundel: (heraldry) a charge in the shape of a filled circle
armorial bearing: heraldry consisting of a design or image depicted on a shield

Other hypernyms of roundel include bearing, charge, heraldic bearing.

roundel (noun)	armorial bearing (noun)
round piece of armor plate that protects the armpit	heraldry consisting of a design or image depicted on a shield
(heraldry) a charge in the shape of a filled circle
English form of rondeau having three triplets with a refrain after the first and third